Characterization and optimization of lyophilization and storage conditions of Leech saliva extract from the tropical leech Hirudinaria manillensis

The medicinal Malaysian leeches have been used in traditional medicine to treat many different ailments. In this study, leech saliva extract [LSE] was collected from the medicinal Malaysian leech Hirudinaria manillensis. Gel electrophoresis of LSE was carried out to estimate the peptide and protein molecular weights of its content. Results showed that LSE contains more than 60 peptides and proteins with molecular masses ranging from 1.9-250kDa. Thrombin time assay in vitro was employed to assess the collected LSE antithrombin activity. First, to study its stability, LSE was lyophilized under the following different conditions: pre-freezing temperature, type of container and lyophilization cycle. Pre-freezed LSE sample at -20°C and lyophilized for 24 hours retained about 100-95% of its original biological activities. Second, the LSE antithrombin activity was monitored for a period of six months. Storage temperature, type of the container and photosensitivity effects on antithrombin activity of the lyophilized [solid state] and non-lyophilized [liquid state] were investigated. Results showed that storage temperature drastically affected the biological activity of LSE with -20°C as the optimum temperature. Samples stored at ambient temperature and +4°C were light photosensitive and adversely affected when stored in polypropylene tubes. Lyophilized samples were more stable than non-lyophilized ones over the period of study. To sum up, in order to have a biologically active stock of LSE, it has to be lyophilized for no more than 24 hours following freezing at -20°C and has to be stored at -20°C in glass tubes protected from light

Variation in bioactive principles of Artemisia amygdalina Decne. in wild and tissue culture regenerants

Wild and tissue culture raised regenerants of Artemisia amygdalina, a critically endangered and endemic plant of Kashmir and North West Frontier Provinces of Pakistan were screened for the amount of bioactive principles and in particular antimalarial compound artemesinin. Phytochemical screening of extracts revealed the presence of terpenes, alkaloids, phenolics, tannins [polyphenolics], cardiac glycosides and steroids in wild [aerial, inflorescence] and tissue culture regenerants [in vitro grown plant, callus and green house acclimatized plants]. HPLC of Artemisia amygdalina revealed the presence of artemesinin in petroleum ether extracts of wild aerial part, tissue culture raised plant and green house acclimatized plants. Acetonitrile and water in 70:30 ratios at flow rate of 1ml/min was standardised as mobile phase. Retention time for standard chromatogram was 6.7. Wild inflorescences and callus does not produce artemesinin. This is the first report of phytochemical screening and artemesinin estimation of wild and tissue culture raised regenerants of Artemisia amygdalina

Cell cross-talk and interactions: a review of structure and function

Cell-cell interactions are central to the function of many organ systems. The contact between cells and their microenvironment is fundamental both during development and for the preservation of tissue structure. Picking out the signals coming from the surrounding environment enables cells to react promptly to changes that may occur. This work provides a comprehensive review on cell interactions and cross-talk in normal physiological and some pathological conditions of different tissues and organs of the human body [e.g. embryonic, vascular, dendritic, natural killer, cardiac, nerve, lung, testicular, epidermal, and dermal cells]. It aimed to explore the nature of this phenomenon and its role in regulating or directing normal cellular function. The mode of cellular interaction was discussed on the basis of biochemical data regarding cytokines or through actual cell contact through different types of junctions or synaptic ribbons. Further understanding of how cell-cell interactions modulate tissue function will allow us to gain fundamental biological insight as well as suggest approaches that will allow the manipulation of tissue function in vitro and for therapeutic applications in vivo

Estudos microbiológicos e químicos do fungo marinho Scolecobasidium arenarium / Microbiological and chemical studies of the marine fungus Scolecobasidium arenarium

A micologia marinha e uma fonte promissora para a descoberta de novas moleculas bioativas, so que muito pouco explorada. Por este motivo nos incentivamos a dar inicio ao primeiro projeto no Brasil no estudo de um fungo marinho, frente a descoberta de novos produtos naturais provenientes de fungos marinhos. Uma linhagem desconhecida de um fungo marinho, denominado SS99F-6, foi isolada de sedimentos marinhos coletados no litoral norte do Estado de Sao Paulo; Posteriormente foi identificada como sendo o fungo marinho Scolecobasidium arenarium. O fungo foi submetido a fermentacao de pequena escala, objetivando a producao de metabolitos secundarios. Os metabolitos secundarios. Os metabolitos secundarios produzidos foram isolados atraves de varias tecnicas cromatograficas, resultando em 5 moleculas. Tres moleculas foram identificadas como dicetopiperazinas, sendo: a conhecida ciclo [Pro-Val] e duas novas na literatura, a ciclo [Phe-Leu] e a ciclo [Ile-Val]. As outras duas moleculas contem compostos aromaticos, no entanto nao puderam ser caracterizadas totalmente.